Comparison analysis on the rock breakage pressure induced by abrasive water jets and abrasive gas jets

In order to verify the feasibility of rock breaking by abrasive gas jet,the effect of abrasive water jet and abra- sive gas jet on rock breaking is compared and analyzed. In this paper,the mechanism of abrasive acceleration in abra- sive water jet and abrasive gas jet is theoretically analyzed. The numerical relationship between the abrasive kinetic en- ergy and inlet pressure of abrasive water jet and abrasive gas jet is obtained. Based on the unified strength theory,the energy criterion for rock breaking by abrasive jet is established,and the critical energy required for rock failure is ob- tained. Based on the accelerated theory of abrasive and the critical energy of rock failure,the critical rock velocity and the required inlet pressure of rock are calculated. Based on the theoretical calculation results,the crushing effect of ab- rasive water jet and abrasive gas jet on limestone erosion is experimentally studied. The results show that when the ab- rasive speed reaches 270 m / s,the required gas jet pressure theoretical value is 15 MPa,the water jet pressure theoretical value is 45 MPa. Two kinds of abrasive jet erosion pits are shaped with “V” type. Compared with the abrasive gas jet,the shape of the crater of abrasive water jet has the characteristics of “small mouth” and “ deep pit”. The size of the erosion crater formed by the abrasive gas jet is larger than that of the abrasive water jet.